#!/usr/bin/env node
import fs from 'node:fs';
import {
  buildControlSchemaSql,
  createSqliteSnapshot,
  inspectSqliteDatabase,
  migrateSqliteSnapshot,
  provisionUserSpace,
} from '../mindspace-userdata-postgres.mjs';

function usage() {
  return `
Usage:
  node scripts/migrate-mindspace-sqlite-to-postgres.mjs --source <sqlite> --user-id <uuid> [--apply] [--replace-shadow]

Default is read-only dry-run. --apply requires MINDSPACE_USERDATA_PG_URL.
The command creates a consistent SQLite snapshot and never modifies the source SQLite.
`.trim();
}

export function parseArgs(argv = []) {
  const options = { apply: false, replaceShadow: false, source: '', userId: '', help: false };
  for (let index = 0; index < argv.length; index += 1) {
    const arg = argv[index];
    if (arg === '--apply') options.apply = true;
    else if (arg === '--replace-shadow') options.replaceShadow = true;
    else if (arg === '--source') options.source = argv[++index] ?? '';
    else if (arg === '--user-id') options.userId = argv[++index] ?? '';
    else if (arg === '--help' || arg === '-h') options.help = true;
    else throw new Error(`未知参数：${arg}`);
  }
  if (!options.help && (!options.source || !options.userId)) throw new Error('--source 和 --user-id 必填');
  return options;
}

export async function run(argv = process.argv.slice(2), env = process.env) {
  const options = parseArgs(argv);
  if (options.help) {
    console.log(usage());
    return { mode: 'help' };
  }
  const inspected = inspectSqliteDatabase(options.source);
  const sourceRows = inspected.tables.reduce((total, table) => total + table.rows.length, 0);
  if (!options.apply) {
    console.log(JSON.stringify({
      mode: 'dry-run',
      userId: options.userId,
      source: inspected.path,
      sizeBytes: inspected.sizeBytes,
      tables: inspected.tables.map((table) => ({ name: table.name, rows: table.rows.length })),
      sourceRows,
      note: '未修改 SQLite 或 PostgreSQL；使用 --apply 才会创建影子空间。',
    }, null, 2));
    return { mode: 'dry-run', tableCount: inspected.tables.length, sourceRows };
  }
  if (!env.MINDSPACE_USERDATA_PG_URL) throw new Error('--apply requires MINDSPACE_USERDATA_PG_URL');
  const snapshotPath = createSqliteSnapshot(options.source);
  const snapshot = inspectSqliteDatabase(snapshotPath);
  const { default: pg } = await import('pg');
  const client = new pg.Client({ connectionString: env.MINDSPACE_USERDATA_PG_URL });
  try {
    await client.connect();
    await client.query(buildControlSchemaSql());
    await provisionUserSpace(client, options.userId, {
      sourceSqlitePath: inspected.path,
    });
    const result = await migrateSqliteSnapshot(client, snapshot, options.userId, {
      replaceShadow: options.replaceShadow,
      sourcePath: inspected.path,
    });
    if (result.sourceRows !== result.targetRows) throw new Error('迁移行数校验失败');
    console.log(JSON.stringify({ mode: 'shadow', ...result }, null, 2));
    return { mode: 'shadow', ...result };
  } finally {
    await client.end().catch(() => {});
    fs.rmSync(snapshotPath, { force: true });
  }
}

if (import.meta.url === `file://${process.argv[1]}`) {
  run().catch((error) => {
    console.error(error instanceof Error ? error.message : error);
    process.exitCode = 1;
  });
}